From 923f09976e51a502b4ec567ce43276e0210b4e0f Mon Sep 17 00:00:00 2001
From: Mark Spanbroek <mark@spanbroek.net>
Date: Wed, 30 Oct 2024 11:25:24 +0100
Subject: [PATCH] update certificates for older blocks

---
 mysticeti/validator.nim                    |  4 ++-
 mysticeti/validator/rounds.nim             |  7 ------
 tests/mysticeti/validator/testMultiple.nim | 29 ++++++++++++++++++++++
 tests/mysticeti/validator/testRounds.nim   | 16 ------------
 4 files changed, 32 insertions(+), 24 deletions(-)

diff --git a/mysticeti/validator.nim b/mysticeti/validator.nim
index 89a75e0..d4d3b66 100644
--- a/mysticeti/validator.nim
+++ b/mysticeti/validator.nim
@@ -53,7 +53,9 @@ func updateSkipped(validator: Validator, supporter: Block) =
         slot.skipBy(stake)
 
 func updateCertified(validator: Validator, certificate: Block) =
-  without (proposing, voting, _) =? validator.rounds.wave:
+  without certifying =? validator.rounds.latest.find(certificate.round) and
+          voting =? certifying.previous and
+          proposing =? voting.previous:
     return
   for proposal in proposing.proposals:
     var support: Stake
diff --git a/mysticeti/validator/rounds.nim b/mysticeti/validator/rounds.nim
index d2675a3..5990b38 100644
--- a/mysticeti/validator/rounds.nim
+++ b/mysticeti/validator/rounds.nim
@@ -16,13 +16,6 @@ func oldest*(rounds: Rounds): auto =
 func latest*(rounds: Rounds): auto =
   rounds.latest
 
-func wave*(rounds: Rounds): auto =
-  # A wave consists of 3 rounds: proposing -> voting -> certifying
-  let certifying = rounds.latest
-  if voting =? certifying.previous:
-    if proposing =? voting.previous:
-      return some (proposing, voting, certifying)
-
 func addNewRound*(rounds: var Rounds) =
   rounds.latest = Round[Rounds.Signing, Rounds.Hashing].new(rounds.latest)
 
diff --git a/tests/mysticeti/validator/testMultiple.nim b/tests/mysticeti/validator/testMultiple.nim
index 4395baa..14b7860 100644
--- a/tests/mysticeti/validator/testMultiple.nim
+++ b/tests/mysticeti/validator/testMultiple.nim
@@ -258,6 +258,35 @@ suite "Multiple Validators":
     validators[0].receive(validators[0].check(certificates[2]).blck)
     check validators[0].status(round, author) == some SlotStatus.commit
 
+  test "commits blocks that are certified by blocks that are received later":
+    # first round: proposing
+    let proposals = exchangeProposals()
+    # second round: first validator does not receive votes
+    nextRound()
+    discard exchangeProposals {
+      1: @[1, 2, 3],
+      2: @[1, 2, 3],
+      3: @[1, 2, 3]
+    }
+    # third round: first validator does not receive certificates
+    nextRound()
+    discard exchangeProposals {
+      1: @[1, 2, 3],
+      2: @[1, 2, 3],
+      3: @[1, 2, 3]
+    }
+    # fourth round: first validator receives votes and certificates, because
+    # they are the parents of the blocks from this round
+    nextRound()
+    discard exchangeProposals {
+      1: @[0, 1, 2, 3],
+      2: @[0, 1, 2, 3],
+      3: @[0, 1, 2, 3]
+    }
+    let round = proposals[0].blck.round
+    let author = proposals[0].blck.author
+    check validators[0].status(round, author) == some SlotStatus.commit
+
   test "can iterate over the list of committed blocks":
     # blocks proposed in first round, in order of committee members
     let first = exchangeProposals().mapIt(it.blck)
diff --git a/tests/mysticeti/validator/testRounds.nim b/tests/mysticeti/validator/testRounds.nim
index 0c3d500..a3696fb 100644
--- a/tests/mysticeti/validator/testRounds.nim
+++ b/tests/mysticeti/validator/testRounds.nim
@@ -51,19 +51,3 @@ suite "List of Validator Rounds":
     rounds.removeOldestRound()
     expect Defect:
       rounds.removeOldestRound()
-
-  test "a wave consists of the last three rounds":
-    var rounds = Rounds.init(slots = 4)
-    rounds.addNewRound()
-    check rounds.wave.isNone
-    rounds.addNewRound()
-    var wave: (Round, Round, Round)
-    wave = !rounds.wave()
-    check wave[0].number == 0
-    check wave[1].number == 1
-    check wave[2].number == 2
-    rounds.addNewRound()
-    wave = !rounds.wave()
-    check wave[0].number == 1
-    check wave[1].number == 2
-    check wave[2].number == 3